/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

package org.apache.iotdb.tsfile.read.common.block.column;

import org.apache.iotdb.tsfile.file.metadata.enums.TSDataType;

import java.io.DataOutputStream;
import java.io.IOException;
import java.nio.ByteBuffer;

public class Int32ArrayColumnEncoder implements ColumnEncoder {

    @Override
    public Column readColumn(ByteBuffer input, TSDataType dataType, int positionCount) {

        // Serialized data layout:
        //    +---------------+-----------------+-------------+
        //    | may have null | null indicators |   values    |
        //    +---------------+-----------------+-------------+
        //    | byte          | list[byte]      | list[int32] |
        //    +---------------+-----------------+-------------+

        boolean[] nullIndicators = ColumnEncoder.deserializeNullIndicators(input, positionCount);

        if (TSDataType.INT32.equals(dataType)) {
            int[] values = new int[positionCount];
            if (nullIndicators == null) {
                for (int i = 0; i < positionCount; i++) {
                    values[i] = input.getInt();
                }
            } else {
                for (int i = 0; i < positionCount; i++) {
                    if (!nullIndicators[i]) {
                        values[i] = input.getInt();
                    }
                }
            }
            return new IntColumn(0, positionCount, nullIndicators, values);
        } else if (TSDataType.FLOAT.equals(dataType)) {
            float[] values = new float[positionCount];
            if (nullIndicators == null) {
                for (int i = 0; i < positionCount; i++) {
                    values[i] = Float.intBitsToFloat(input.getInt());
                }
            } else {
                for (int i = 0; i < positionCount; i++) {
                    if (!nullIndicators[i]) {
                        values[i] = Float.intBitsToFloat(input.getInt());
                    }
                }
            }
            return new FloatColumn(0, positionCount, nullIndicators, values);
        } else {
            throw new IllegalArgumentException("Invalid data type: " + dataType);
        }
    }

    @Override
    public void writeColumn(DataOutputStream output, Column column) throws IOException {

        ColumnEncoder.serializeNullIndicators(output, column);

        TSDataType dataType = column.getDataType();
        int positionCount = column.getPositionCount();
        if (TSDataType.INT32.equals(dataType)) {
            for (int i = 0; i < positionCount; i++) {
                if (!column.isNull(i)) {
                    output.writeInt(column.getInt(i));
                }
            }
        } else if (TSDataType.FLOAT.equals(dataType)) {
            for (int i = 0; i < positionCount; i++) {
                if (!column.isNull(i)) {
                    output.writeInt(Float.floatToIntBits(column.getFloat(i)));
                }
            }
        } else {
            throw new IllegalArgumentException("Invalid data type: " + dataType);
        }
    }
}
